Hollow carbon nanofibers as high-performance anode materials for sodium-ion batteries

Hollow carbon nanofibers (HCNFs) are successfully fabricated by pyrolyzation of a polyaniline hollow nanofiber precursor. The as-prepared HCNFs as sodium storage anode materials exhibit a high reversible charge capacity of 326 mA h g(-1) at 20 mA g(-1), high rate capability (85 mA h g(-1) at 1.6 A g(-1)) and superior cycling stability (a capacity retention of 70% even after 5000 cycles at 1.6 A g(-1)). Such a high performance of HCNFs can be ascribed to the special hollow structure characteristics; they possess a well fabricated electronic transport path and can shorten the ion diffusion distance. Therefore, the HCNFs can be regarded as promising anode materials for advanced sodium ion batteries (SIBs).